Have you ever used a calculator? It’s an almost magical toy: you press buttons that have numbers on them, and the calculator adds them for you, or multiplies them, or whatever else you want to do, then shows the answer. So Bedtime Math fan Abby W. asked, how many buttons do 100 calculators have on them? (She also sent this fun drawing!) Well, that depends on the number of buttons. The simplest calculator has 10 buttons for the “digits” — 0, 1, 2, 3 all the way up to 9 — and the buttons to add, subtract, multiply, divide, an equal sign, and a “clear” button to start over. That’s at least 16 buttons. But there are LOTS of other cool math buttons on grown-up calculators: buttons that do the math on angles or money, or that tell you how many times to multiply a number by itself. Even with a simple calculator, though, you can make the numbers grow fast.
Wee ones: If you’ve pressed buttons 1, 2, and 3, what button should you press next to stay in order?
Little kids: If you press 1, then 2, then 1 again, then 3, then 1, then 4…what’s the next button you press? Bonus: If you type 707 (which spells “LOL” upside-down), then add 1, what number do you have now?
Big kids: If 2 to the 3rd power means 2 x 2 x 2, what does 3 to the 3rd power equal? Bonus: If Abby had 100 of those 16-button calculators, how many buttons would they have all together?
Wee ones: The 4.
Little kids: The 1. Bonus: 708.
Big kids: It equals 3 x 3 x 3, or 27. Bonus: 1,600 buttons.
Laura Bilodeau Overdeck is founder and president of Bedtime Math Foundation. Her goal is to make math as playful for kids as it was for her when she was a child. Her mom had Laura baking before she could walk, and her dad had her using power tools at a very unsafe age, measuring lengths, widths and angles in the process. Armed with this early love of numbers, Laura went on to get a BA in astrophysics from Princeton University, and an MBA from the Wharton School of Business; she continues to star-gaze today. Laura’s other interests include her three lively children, chocolate, extreme vehicles, and Lego Mindstorms.